This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 11-277337, filed Sep. 29, 1999, the entire contents of which are incorporated herein by reference.
The present invention relates to a pipe coupling for engine oil change which is comprised of a drain plug to be attached to and detached from the oil drain port of an engine oil pan and a socket detachably attached to the drain plug and, to a drain plug for engine oil change with which, when the engine oil is changed, it can be drained easily without removing the drain plug.
Conventionally, an engine uses engine oil to cool or lubricate components in the engine. When the engine oil deteriorates, it is drained the outside the engine through a drain plug provided to an engine oil pan, so that the old engine oil can be changed for new engine oil. When it is time to change engine oil, the drain plug must be removed and the engine oil must be drained at an auto repair shop or the like.
This engine oil change takes time since the drain plug attached to the engine oil pan must be removed, the oil must be drained, and after that the drain plug must be attached to the engine oil pan again. During the change, the oil may be spilled to soil the repair shop. If the engine oil is changed often, the screw of the drain plug may be worn or damaged to cause oil leakage from this portion.
It is, therefore, an object of the present invention to provide a pipe coupling for oil change in which a flow path is formed in a drain plug, a valve is provided to the flow path, and when a mating socket is connected to the drain plug, the valve opens the flow path to allow the oil in the oil pan to be drawn, so that conventional drain plug attaching/detaching operation is eliminated and efficiency in engine oil change is improved. It is another object of the present invention to provide a pipe coupling for oil change in which, since a plug constituting the pipe coupling is a drain plug to be attached to an engine oil pan, the projecting amount of the plug from the engine oil pan can be made as small as possible, when a stone or the like hits the drain plug, the drain plug will not be damaged easily, and a valve in the drain plug will not be manually opened easily.
According to one aspect of the present invention, there is provided a pipe coupling used for changing oil in an engine oil pan with an oil drain port. This pipe coupling comprises a drain plug to be attached to the oil pan, the drain plug having a drain plug main body with one end to be attached to the oil drain port of the engine oil pan, the other end projecting outward from the oil pan, a recess formed on an outer surface of the other end, and an axial hole capable of communicating with an interior of the oil pan and forming an oil flow path, a valve holder arranged, in the axial hole, at a front position of the other end, and having an end face facing outward, and a valve body held by the valve holder and capable of closing the flow path. This pipe coupling also comprises a socket which can be connected to the drain plug. The socket has a socket main body with one end that can be mounted on the other end of the drain plug, and an axial hole capable of communicating with the axial hole in the plug main body and forming an oil flow path, a seal member arranged in the axial hole of the socket main body to engage with the end face of the valve holder when one end of the socket main body is mounted on the other end of the drain plug, a plurality of locking members provided to the socket main body and capable of engaging with the recess when one end of the socket main body is mounted on the other end of the drain plug, and a slide sleeve mounted on an outer surface of the socket main body to be movable in an axial direction and capable of holding a state wherein the locking member engages in the recess. The valve body opens the oil flow path when one end of the socket main body is mounted on the other end of the drain plug.
According to the pipe coupling according to the present invention, when the socket is connected to the drain plug, the valve body provided in the drain plug opens the oil flow path. Thus, oil can be drawn into the engine oil pan. Thus, the conventional drain plug mounting/attaching operation is not necessary, the labor needed for engine oil change can be decreased, and the operation time can be shortened.
The valve holder is preferably a member separate from the drain plug main body, and is further preferably fixed to the drain plug main body by caulking. In this case, the outward projecting amount of the drain plug from the engine oil pan can be reduced.
If the valve body has an end face to be arranged on an axially inner side than the end face of the valve holder, damage to the valve body, which may occur when a stone or the like collides against the drain plug, can be prevented.
According to an another aspect of the present invention, there is provided a drain plug for a pipe coupling designed to change oil in an engine oil pan that has a drain port. The drain plug comprises a main body having a first end part to be attached to the drain port of the oil pan, a second end part projecting outwards from the oil pan, a recess made in an outer surface of the second end part, and an axial hole forming an oil path and capable of communicating with an interior of the oil pan; a valve holder provided in the axial hole, positioned near the second end part and having a face exposed to outside; and a valve body held in the valve holder, for closing the oil path.